From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D317EC3A59B for ; Sat, 17 Aug 2019 19:41:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A42AE21744 for ; Sat, 17 Aug 2019 19:41:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726215AbfHQTlN (ORCPT ); Sat, 17 Aug 2019 15:41:13 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:55578 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726067AbfHQTlN (ORCPT ); Sat, 17 Aug 2019 15:41:13 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::d71]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 3864914DB6E1C; Sat, 17 Aug 2019 12:41:12 -0700 (PDT) Date: Sat, 17 Aug 2019 12:41:11 -0700 (PDT) Message-Id: <20190817.124111.708318885882893287.davem@davemloft.net> To: idosch@idosch.org Cc: netdev@vger.kernel.org, nhorman@tuxdriver.com, jiri@mellanox.com, toke@redhat.com, dsahern@gmail.com, roopa@cumulusnetworks.com, nikolay@cumulusnetworks.com, jakub.kicinski@netronome.com, andy@greyhouse.net, f.fainelli@gmail.com, andrew@lunn.ch, vivien.didelot@gmail.com, mlxsw@mellanox.com, idosch@mellanox.com Subject: Re: [PATCH net-next v3 00/16] Add drop monitor for offloaded data paths From: David Miller In-Reply-To: <20190817132825.29790-1-idosch@idosch.org> References: <20190817132825.29790-1-idosch@idosch.org> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Sat, 17 Aug 2019 12:41:12 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Ido Schimmel Date: Sat, 17 Aug 2019 16:28:09 +0300 > Users have several ways to debug the kernel and understand why a packet > was dropped. For example, using drop monitor and perf. Both utilities > trace kfree_skb(), which is the function called when a packet is freed > as part of a failure. The information provided by these tools is > invaluable when trying to understand the cause of a packet loss. > > In recent years, large portions of the kernel data path were offloaded > to capable devices. Today, it is possible to perform L2 and L3 > forwarding in hardware, as well as tunneling (IP-in-IP and VXLAN). > Different TC classifiers and actions are also offloaded to capable > devices, at both ingress and egress. > > However, when the data path is offloaded it is not possible to achieve > the same level of introspection since packets are dropped by the > underlying device and never reach the kernel. > > This patchset aims to solve this by allowing users to monitor packets > that the underlying device decided to drop along with relevant metadata > such as the drop reason and ingress port. ... Looks great, series applied, thanks.